Spam and Telemarketing

Over the last few decades I've heard quite a bit of complaining about telemarketers. Over the last decade it's been about spam. There's an easy solution. If telephone numbers and email addresses were viewed as private property, an owner could post a "no trespassing" or "no soliciting" sign, and telemarketers and spammers could be held criminally liable for trespassing when they send their unwanted messages, with restitution owed the owner. Also, I'm surprised that phone companies and ISP's haven't taken to using passwords for everyday phone calls and emails. Maybe things are already this way and I haven't noticed. Or maybe phone numbers and email addresses really aren't private property after all. Anybody out there know?